Communication devices that capture and transmit and/or store acoustic signals often use noise reduction techniques to provide a higher quality (i.e., less noisy) signal. Noise reduction may improve the audio quality in communication devices such as mobile telephones which convert analog audio to digital audio data streams for transmission over mobile telephone networks.
A device that receives an acoustic signal through a microphone can process the acoustic signal to distinguish between a desired and an undesired component. A noise reduction system based on acoustic information alone can be misguided or slow to respond to certain changes in environmental conditions.
There is a need to increase the quality and responsiveness of noise reduction systems to changes in environmental conditions.